Composite pipe structure



June 20, 1950 w, H, s E 2,512,116 Q COMPOSITE PIPE STRUCTURE Filed July 1, 1947 fligul.

@ 1 4 l M i z w 5 5 1 "'7 w ll? 9 i r 1' P i n l a 3 a 5 2 i -9 v mill-I l" 5 INENTOR.

A TTOHA/EY Patented June 20, 1 950 j UNITED STATES PATENT OFFICE f 2,512,116 l COMPOSITE PIPE STRUCTURE William H. Siebels, San Francisco, Calif. Application July 1, 1947, Serial No. 758,351

4 Claims.

spaced from the inner pipe, and a number of spacing elements interposed between the pipes for maintaining them in concentrically spaced relationship, whereby an annular air channel is provided between the pipes for ventilation and cooling purposes.

' Another object of my invention is to provide an improved composite pipe structure of the kind characterized, embodying novel spacing elements which in assembly, makes it possible to conveniently connect one section to another, and which after assembly, function to maintain the inner and outer pipes in concentric spaced relationship.

Other and further objects of my invention will ,be pointed out hereinafter, or will be indicated in the appended claims, or will be obvious to one skilled in the art upon an understanding of the present disclosure. For the purpose of this application, I have elected to show herein certain forms and details of a composite pipe structure embodying my invention. It is to be understood however, that the embodiment of my invention shown and described herein is for illustration purposes only and that therefore it is not to be regarded as exhaustive of the variations of the invention.

In the accompanying drawings:

Fig. 1 is a longitudinal sectional view of a number of joined sections of my composite pipe, showing the spacing elements in operative positions between the inner and outer pipes;

Fig. 2 is a side elevation, partly in section, of a number of pipes, showing diagrammatically the manner in which the sections are joined to one another;

Fig. 3 is a sectional view taken on the line 3--3 of Fig. 1; and

Fig. 4 is a perspective View of the spacing element.

As shown in the drawings the joined sections of my composite pipe structure each comprises an inner core pipe I having its male end crimped as at 2 and its opposite female end of larger diameter so as to receive the crimped male end of the inner core pipe of an adjoining section. The outer pipe 3 of each section is similarly con- :structed with a crimped male end 4 and a female end of larger diameter which'is adapted to receive the crimped male end of the outer pipe of an adjoining section. Each section is preferably assembled with the crimped male end 2 of the inner core pipe 1 adjacent the larger female end of the outer pipe 3. The crimped male end 2 of the inner pipe points downwardly and fits in the upper female end of the inner pipe I of the adjoining lower section, while the reverse is true with respect to the outer pipe, the crimped male end 4 of the outer pipe 3 pointing upwardly to be inserted'in the uncrimped female end of the superimposed outer pipe of the section above. By assembling the sections in this manner moisture such as rain, running down the exterior surface of the joined outer pipes 3, and condensates forming inside the inner pipes I, are carried over the joints so that no moisture or corrosive fluid enters the annular space between the inner and outer pipes.

The inner and outer pipes of each section are maintained in concentric spaced relation by space ing elements 5, thereby providing an annular longitudinal air channel which is particularly suitable for ventilation and cooling purposes. The spacing elements each comprise a substantially circular metal strip 6 of thin somewhat resilient material having a number of spaced substantially hemi-spherical convex and hollow protuberances formed thereon. The ends of each strip is. formed with these protuberances 1, and in assembly one of them nests inside the other. The strips" 6 of the spacing elements 5 are adapted to extend circumferentially around an inner pipe I and closely engage therewith, while the protu berances l are adapted to engage with an outer pipe 3 and maintain it in spaced concentric relation to the inner pipe. The two end protuberances I of each strip are normally maintained in contacting relation one within the othe by reason of the engagement of the outer pipe 3 with.

the outer protuberance I, thereby preventing the relative displacement of the two contacting end protuberances. It is to be noted that the length of the radius of each protuberance l is substantially equal to the distance between the inner and outer pipes, thereby making it possible for the spacing elements 5 to properly fit between the inner and outerpipes and normally hold them against relative displacement. The inner pipe I of each section is formed with pairs of outwardly disposed spaced and parallel annular protuberances 8' between which the spacing elements are positioned. The annular protuberances 8 of each pair are suitably spaced one from the other to provide means for normally preventing the longitudinal displacement of a spacing element 5 located between. In each pipe section one pair of spaced annular protuberances 8 is positioned near the female end of the inner pipe I and the other pair of said protuberances is positioned near the mid-portion of said inner pipe. The outer pipe 3 of each section is formed with annular interior grooves 9 near its opposite ends, and in assembly the protuberances I of the spacing elements 5 are adapted to engage with the said grooves to prevent the relative displacement of the inner and outer pipes.

In connecting the section one to another the outer pipe 3 is held stationary while the inner pipe I is pulled downwardly until the centrally dis posd spacing element 5 thereof is carried to a position in which its protuberances' I engage with the lower annular groove 9 of the outer pipe.

When so positioned the protuberances i engaging t bq it en 12119; a more. t-he s d c t r ei i e eae e f rele neaiplben the p tim o e inn c o, v ma ien'ee iire r'ie i jsa ci ed e eu e'ane ena a eneti een- 1? inoved upwardly to a position in which} I ma e ndfl 9 h l we mi er p eeeete san-d h. the-let enealeenaetih e-b es -When the nner and outer pipes of both hu onnec d h c na elai e seatin elements 5- a th id normally prevent their longitudinal dis- 2i a ot t iet n e ie imey groove. Each pair of annular protuberances 8 on the inner pipe I are of suflicient height to prevent the longitudinal displacement of its associated spacing element when the latter is perm ted to expand by the protuberances 1 thereof entering a groove 9 of the outer pipe.

It is contemplated that the strip material from which the spacing elements 5 are subsequently out be formed with the convex protuberances I in the usual manner, and that it then be packaged in rolls for use in the required'leng'thsas needed.

What- I claim is:

1. In composite pipe of the kind having inner and outer tubular pipes, a spacing element for norinallyma'intaining the two pipes in annularly sp'aedrelatior'i comprising a split resilient band encircling the inner pipe and having its opposite ends detachably joined together and a plurality of spaced protuberances formed on the band for engaging with the outer pipe.

.2 9 11. 1. p es 9i the kiwi having inn anti oute A a paqie element fo normally in ining the two pipes in annularly spaced and substan ially win make an 9 m e. 1 e an Qsz rwtable s lit ban encirqn the nner i e-e isi ie ie i a nulmhe e ced pr tuberance o ulqstentiall uniiQ emoti ns in ee a 'm nt ith t e out r In gqmpoeitenimfl the ind hailin i ne and inter ubules; ipes a s ac n ele en f r mental main ain n he the ipes in annulaitl spaced and substantially concent crelation pornmr siee a es ient meta spl t bane et bl he a en ag n ie inerripe mi harms. a 1%: in c; ma 11w spaced: niteti herenpee a ran ai e enga n relatie the Out r; ipe the saicihans hf' riee. We? p lpfi e b the emsq ted bu e aeeiaha he A. ante 1Tl'% 35 ies/ g relation.

The. izollowing references. are, of record in the file of this. patent:

UNITED STATES PATEN'IE;

Number Name Date. D."l49,396 Babin Apr. 27,, 1948 2,Q76,2'l0- Stadtfeld Apr. 6, 1937 2 2594433 Kitto Oct. 14, 1941 2,273,393. Couty' Heb. 17, 1942 

